Blow/fill/seal machines are commonly used for aseptic packaging of pharmaceutical products; especially biologicals, proteins, and like substances. To ensure aseptic packaging conditions, the product path and fill assemblies of these machines must be sterilized from time to time. Such sterilization usually is effected by high pressure steam at 110° C. to 125° C.; however, the available steam sterilization techniques are cumbersome and time consuming when applied to larger open volumes.